Emacs. It's what I started with, and it feels very natural to use. But I went to PyCon and saw almost everyone using vim, and very few people using emacs.
As a high school teacher, I want to be comfortable in emacs and vim. I want to be able to show students both, and help them pick the one that works best for them.
Vim. It's fast, very powerful, installed on every server I ssh to, very powerful, great syntax highligting for many languages, easy on my wrists, great plugins.
Gedit. Why? Ubuntu is my preferred OS distro and it comes pre-installed. It's pretty cool and lets me do text editing and scripting / programming for smaller projects.
## Honorable mentions
Scite, SublimeText 2, Leafpad (Xfce), Notepad++ etc.
Geany. Simple and lightweight. I can run the local server from the built in terminal which is great because I can easily find program outputs among all the other windows I have open.
Vim - because its everywhere and controlling it doesn't require much typing (I suffer from hands problems). Emacs - because it's so extensible and I prefer ELisp over Vimscript.
1. Notepad and Textedit since they are already installed.
2. Very old MS Developer Studio since I'm a creature of habit and I like it.
3. Other IDE editors for specific domains.
Sublime 2 for programming and coda for web development.
I have recently started using Sublime 2 and like it. It is light weight with tons of features.You can use several plugins used in textmate as well as other text editors.
And Coda I use for real time web development (it synchronizes the file to server in real time and you see the result right away)
And tadaaa : http://news.ycombinator.com/item?id=3717754
Anyway... I use SublimeText 2 too.